1. Field of the Invention
This invention relates generally to shock absorbers, and more particularly, to an improved adjustable hydraulic shock absorber of the dashpot type. The adjustable shock absorber of the present invention is adapted for many uses, as for example, for controlling the movement of various machine mechanisms and absorbing vibrations of varying quantities of kinetic energy.
2. Description of the Prior Art
It is known in the hydraulic dashpot art to provide a pressure tube filled with fluid, and to have a piston slidably mounted therein which carries a piston rod for receiving impact loads. Heretofore, certain prior art hydraulic dashpots have been provided with an internally mounted diaphragm means for forming a reservoir to receive fluid and expand under pressure during an impact load absorbing operation and to contract and force fluid back to the pressure tube after the impact load is removed, and to return the piston to its initial load receiving position. However, such prior art dashpots are not simple and compact in construction, nor are they economical to manufacture. They require separate metering valve means and check valve means, and separate passageways for controlling the flow of fluid between the pressure tube and the reservoir. A disadvantage of the other prior art hydraulic dashpots is that they require a return spring for returning the piston to its initial starting position after the impact load is removed. A further disadvantage of the prior art dash pots is that the fine metering orifices employed tend to clog up.